Rowan Pelling: So Heather posed topless. So? So?

I've done it, and I've persuaded other women to do it. And plenty of men have done a lot worse

This country is so sexually retarded that I am considering moving to a cave in Dorset with an Italian porn star hung like a shire horse, where we will create our own hybrid super-race of Jane-Austen-loving studs and nymphets. On high days and holidays we will hold picnics on the Cerne Abbas giant's penis, and on low days we'll play Scrabble.

Where was I? So Heather Mills McCartney posed for some saucy naked pics some 20 years ago. So? So? So? According to The Sun the photo-shoot amounts to hardcore porn and show Mills McCartney wearing handcuffs, slathering baby oil on to a male porn star, and posed with said model in positions so depraved and disgusting that they would make ordinary Sun readers (who enjoy decent, blameless lifestyles ogling page 3 stunnas) sick at the thought of them. OK, they didn't say that last bit, but it was implied in their claim that many images were too explicit to be published, leaving readers imagining Lady Macca being rogered silly by three hairy bikers in goat masks (or is that just me?).

Meanwhile Lady M's lawyers say the snaps were taken for a "lovers' guide" and "the photo shoot was not pornographic or for the purposes of gratification of the viewer". Whatever. I don't know of any sex manual that isn't intended for a bit of good old-fashioned titillation, otherwise what's the bleedin' point? But even if it was X-rated and involved something as outrageous as the nubile Heather having sex with a man 25 years her senior who looks like an old lady with pursed lips and a bad dye-job, what's the problem? And why should it affect her divorce?

The episode happened when Mills McCartney was at an age when everyone except the dead and lobotomised are guilty of gross folly and indiscretions. Furthermore, from everything I've gleaned, the book doesn't amount to "hardcore" porn. It contains bog-standard photos of simulated sex of the type shown in all sex manuals since some bright spark deduced that the hairy man in The Joy of Sex put readers off their stroke.

But what really amazed me is the opprobrium we dish out to so-called sex scandals as opposed to any other kind of misdemeanour. And never more so than when it's a folie de jeunesse. We have no problem embracing reformed villains such as Jonathan Aitken, Lord Brockett, Johnny Vaughan and D B C Pierre. In fact we tend to mythologise their crimes. But Carole Caplin, Koo Stark and Anouska Hempel (successful professional women for the large part of their lives) are eternally disparaged because in the exuberance of youth they disrobed for some harmless bit of filmic aphrodisia.

And nobody seems to give a damn that one stonking difference between the male transgressors and the ridiculed females is that what the men did was - hello? - illegal. If Lady M's divorce settlement is really jeopardised by a few kinky photos, why shouldn't Lord M be penalised for his drugs offences? And if we're going to start punishing people for legal acts of mild obscenity, why not dock Macca £20m for "The Frog Song"?

This nation's censorious attitude towards sex, born largely of vile prurience, makes us so confused that we think lack of sexual continence or physical inhibition is a crime. I was disturbed some months ago when glancing at the results of a sex survey to see that most Brits thought prostitution should be legalised. It had escaped the readers and editor of the newspaper that prostitution is entirely legal and has been for some time.

This same ethical confusion probably explains why we largely absolve footballers who have been guilty of acts of violence - Jonathan Woodgate - but persecute Stan Collymore. So he went dogging. So? So? So? It was adult and consensual and with any luck ruined the upholstery of some God-awful SUV. If we're going to damn Collymore, shouldn't it be because he beat up Ulrika? If anything demonstrates the wonky dial of our moral compass it's the fact we lauded Leslie Grantham when he was merely guilty of manslaughter, but treated him like Nazi scum for having a quick hand-shandy over the internet in the privacy of his dressing-room.

It's the curse of our age that every sexual indiscretion of every last D-list celeb will one day surface in a bidding war on eBay. The likes of Joan Crawford were lucky to live in a more closeted age when goddesses could tower above mere rumour of their former, less salubrious, incarnations.

Moreover, in certain circles it's modish to disrobe. There are those who've stripped for art (Kate Moss), for a political statement (Germaine Greer), for Vanity Fair (Keira Knightley) or for the Erotic Review (me). I used to persuade all manner of nicely brought-up young women to take their clothes off and felt I could hardly do so unless I was willing to bare some flesh myself. But when posh girls, thespians or bluestockings disrobe it's "art". If it's a street-smart girl on her uppers it's tit's'n'ass and "porn".

The punters don't make such deluded value judgements. I received the following letter after a scantily-clad photo of me was published in a magazine some years ago: "Dear Miss Pelling, I liked the photo of you in the magazine. In fact it was so good that I had to have a wank. Love Geoff." I thought it was funny. Now I am wondering whether I will have to cede custody of our child and all our money to my husband because of the harrowing shame.

Except, fortunately for me, my husband has also stripped naked for a magazine (interested parties should search the GQ archives circa 1993). Let's hope some lewd shots of a young Macca surface to similarly bolster Lady M.